Lead clutch for mechanical pencils



Nov. 19, 1929. w. G. AULMANN 1,736,568

LEAD CLUTCH FOR MECHANICAL PENCILS Filed April 10, 1928 I Wf flwlwazraATTO R N EY Patented Nov. 19, 1929 UNITED STATES WILLIAM G. AULMANN, OFLOS ANGELES, CALIFORNIA LEAD CLUTCH FOR MECHANICAL PENCILS Applicationfiled April 10,

My present invention has reference to a lead clutch for mechanicalpencils of a construction that will prevent the breakage of the lead inits passage through the clutch,

regardless of any irregularities in the lead stick or any irregularitiesof the clutch in the pointed end of the barrel of the pencil.

As is well known lead sticks, commonly become broken in their passagethrough the clutch members of mechanical pencils because such clutchmembers are of rigid formation and likewise owing to irregularities inthe machine work and assembling of such pencils. The breaking of thelead sticks is also occasioned by crookedness or irregularities in suchsticks. With my improvement it is my purpose to provide a clutch throughwhich the lead stick passes which is of a flexible nature, that is, theclutch comprises two members, a lower member being freely journaled orswivelly connected to the upper member so that there will be a yieldingbetween these members to insure the passage of the lead stick withoutdanger of its breaking.

To the attainment of the foregoing the invention consists in theimprovement as hereinafter described and definitely claimed.

In the drawings:

Figure 1 is a side elevation of a mechanical pencil embodying myimprovement, parts being broken away and parts in section.

Figure 2 is an approximately central longi- 5 tudinal sectional view ofthe upper element of the clutch before the lower edge has been turned orrolled in.

Figure 3 is a similar view of the lower element of the clutch.

Figure 4 is a perspective View of the lower clutch section.

Figure 5 is a section through a modification.

Referring now to the drawings in detail, the numeral 1 designates thetubular barrel of a mechanical pencil. On one end of the barrel 1 thereis mounted for turning a knurled head 2 that carries a tube 3 in which50 lead sticks 4 are received. The lower end 1928. Serial No. 268,949.

of the barrel 1 is tapered in the usual manner,

as indicated at 5.

The lower end of the tube 3 is threadedin the well known manner and thisthreaded portion enters the threaded bore or socket of the tubular upperelement 6 of my improved clutch. The element 6 is formed intermediateits ends with an outwardly extending annular shoulder 8 whereby it isfastened in the bore of the tapered point 5. The outer or lower end ofthe element 7 is non-threaded and is bendable. For distinction thesocket provided at this end of the element 7 is indicated by the numeral9 and this socket is designedto receive therein outwar-dly extendingbeads 10 on the lower element 11 of the clutch. After the beaded end 10has been received in the socket 9 the outer end of the member 7 is bentinwardly to provide a swivel connection between the elements 7 and 11.The element 11 has its outer end tapered, as at 12, and is provided withlongitudinal slots 13 whereby the end of this element may be compressedto give the desired frictional grip on the lead.

The beads 10 may be formed on the inner end of the element 11 in anydesired or preferred manner. For instance, and as disclosed by Figures3, and 4, the inner and widened end of the said element 11 may have itssides cutaway and the material between such cut-away portions bentoutwardly to form the beads, or as disclosed by Figure 5 of the drawingsthe slotted clutch element 11 may-have its inner end formed with a continuous round head 14.

My invention presents a distinct improvement on the pencil constructionprotected by U. S. Letters-Patent #1,581,472 and is especially adaptablefor use in Connection there'- wit The simplicity of my construction andthe advantages thereof will, it is thought, be understood andappreciated by those skilled in the art when the foregoing descriptionhas been carefully read in connection with the accompanying drawings,but obviously I do not wish to be restricted to the precise detailsherein set forth and, therefore, hold myself entitled to make suchchanges there from as fairly fall within the scope of what I claim.

Having described the invention, I claim:

1. The combination in a fountain lead pencil, a barrel having a pointedend, a head, a lead carrying tube secured to the bore of thebarrel andhaving athreaded end, of a lead clutch comprising an upper section inwhich the tube is screwed and a lower section which is tapered, slottedand compressed to receive and hold by friction a longitudinally movablelead and which has a loose joint con- 7 nectlon with the upper sectionof the clutch.

2. The combination in a fountain lead pencil, a barrel having a pointedend and a head, a threaded lead carrying tube secured to the bore of thebarrel and securing the head, a lead clutch member through which thelead passes comprising an upper section in which the tube screws and alower section which is tapered, slotted and permanently compressed toreceive and hold by friction a longitudinally movable lead, having beadson the upper end of the tapered member of the clutch and the lower endof the upper section of the clutch having a lip in which is freelyreceived the beaded end of the lower clutch section.

In testimony whereof I'atfiX my signature.

WILLIAM G. AULMANN.

